he emphasis of this project is to use molecular genetics, ncluding recombinant DNA techniques, to understand the athogenesis of gonococcal infections and some other infectious iseases of bacterial etiology. The major area of study nvolves outer surface components, especially outer membrane roteins, and the genes which encode them. Since the best ethod to study the primary structure of a protein is to redict its amino acid sequence from the sequence of the gene, e have concentrated on gene cloning as the first step. The ontrol of expression is also an interesting area of study hich can be pursued by analysis of the cloned DNA segment ncluding the gene(s) of interest. We have used ligonucleotide probes to identify clones of genes encoding uter membrane proteins. A clone of gonococcal PII has been artially characterized. Using this cloned DNA as a probe in outhern blots, we have shown some DNA sequence alteration probably rearrangement) correlated with phenotypes expressing r not expressing the PII proteins. The control of expression nd apparent arrangement of the PII genes seems to have some nteresting differences and similarities to the pattern seen or genes of another virulence factor--gonococcal pili. We ave also synthesized oligonucleotides for several other aboratories within NIAID for use as linkers, DNA sequencing rimers, directed mutagenesis of cloned genes, and probes of loned genes analogous to our own use of them.